The present invention relates to testing data packet transceivers, and in particular, to testing multiple data packet signal transceivers simultaneously.
Many of today's electronic devices use wireless technologies for both connectivity and communications purposes. Because wireless devices transmit and receive electromagnetic energy, and because two or more wireless devices have the potential of interfering with the operations of one another by virtue of their signal frequencies and power spectral densities, these devices and their wireless technologies must adhere to various wireless technology standard specifications.
When deciding such wireless devices, engineers take extra care to ensure that such devices will meet or exceed each of their included wireless technology prescribed standard-based specifications. Furthermore, when these devices are later being manufactured in quantity, they are tested to ensure that manufacturing defects will not cause improper operation, including their adherence to the included wireless technology standard-based specifications.
For testing these devices following their manufacture and assembly, current wireless device test systems employ a subsystem for analyzing signals received from each device. Such subsystems typically include at least a vector signal generator (VSG) for providing the source signals to be transmitted to the device under test, and a vector signal analyzer (VSA) for analyzing signals produced by the device under test. The production of test signals by the VSG and signal analysis performed by the VSA are generally programmable so as to allow each to be used for testing a variety of devices for adherence to a variety of wireless technology standards with differing frequency ranges, bandwidths and signal modulation characteristics.
As part of the manufacturing of wireless communication devices, one significant component of production cost is costs associated with manufacturing tests. Typically, there is a direct correlation between the cost of test and the time required to perform the test. Thus, innovations that can shorten test time without compromising test accuracy or increasing Equipment costs (e.g., increasing costs due to increasing sophistication of necessary test equipment, or testers) are important and can provide significant costs savings, particularly in view of the large numbers of such devices being manufactured and tested.
A recent development in the design and operation of wireless radio frequency (RF) data packet signal transceivers has been the use of multiple inputs and multiple outputs implemented with multiple antennas. In other words, such devices, referred to as multiple-input, multiple-output (MIMO) devices, use multiple antennas for wireless transmission and reception of their data packet signals. Accordingly, when testing such devices provisions are made for testing them in such a way as to exercise their MIMO capabilities. For example, this includes operating the device under test (DUT) such that all of its transmitters and receivers are operating to transmit and receive, respectively, their respective data packet streams via their respective antenna connections. Hence, all transmitters and all receivers can be tested simultaneously.
However, for single-input, single-output (SISO) data packet signal transceivers, such devices require sophisticated dedicated testing hardware to accomplish such simultaneous testing of multiple DUTs, or, alternatively, time consuming sequential testing to avoid higher capital costs associated with such sophisticated test equipment.
Accordingly, it would desirable to have a technique for testing multiple SISO devices more quickly than by purely sequential testing, and while avoiding the need for sophisticated dedicated test equipment.